1. Field
Embodiments of the invention relate to the field of electromagnetic audio speakers; and more specifically, to spiders for use in compact audio speakers.
2. Background
Audio speakers use electrical signals to produce air pressure waves which are perceived as sounds. Many audio speakers use a diaphragm that is movably suspended in a frame by a surround. The diaphragm is coupled to a voice coil assembly that is suspended in a magnetic field. The electrical signals representing the sound flow through the voice coil and interact with the magnetic field. This causes the voice coil and the coupled diaphragm to oscillate in response to the electrical signal. The oscillation of the diaphragm produces air pressure waves.
It is desirable to provide an additional support for the diaphragm and voice coil assembly using a spider. The spider readily flexes in the direction of motion of the diaphragm, but resists motion perpendicular to the diaphragm's motion. The spider surrounds the voice coil assembly in an annular manner.
It is desirable for the spider to be spaced at a distance from the surround to improve the resistance to perpendicular motion. The magnet assembly that provides the magnetic field in which the voice coil assembly is suspended is typically the part of the speaker that is furthest from the surround. The spider is typically attached to the speaker frame above the magnet assembly placing it closer to the surround than the magnet assembly.
Speakers used in compact, portable devices often need to be thin. This requires a construction that reduces the distance between the surround and the magnet assembly. This can make it difficult to attach the spider at a sufficient distance from the surround to effective resist perpendicular motion of the diaphragm and voice coil assembly.
Thus it would be desirable to provide audio speaker that is thin while having a spider attached at a sufficient distance from the surround to effectively resist perpendicular motion of the diaphragm and voice coil assembly.